Inflatable protective cushions used in passenger vehicles are a component of relatively complex passive restraint systems. The main elements of these systems are: an impact sensing system, an ignition system, a propellant material, an attachment device, a system enclosure, and an inflatable protective cushion. Upon sensing an impact, the propellant is ignited causing an explosive release of gases filing the cushion to a deployed state which can absorb the impact of the forward movement of a body and dissipate its energy by means of rapid venting of the gas. The entire sequence of events occurs within about 30 milliseconds. In the undeployed state, the cushion is stored in or near the steering column, the dashboard, in a door, or in the back of a front seat placing the cushion in close proximity to the person or object it is to protect.
Inflatable cushion systems commonly referred to as air bag systems have been used in the past to protect both the operator of the vehicle and passengers. Systems for the protection of the vehicle operator have typically been mounted in the steering column of the vehicle and have utilized cushion constructions directly deployable towards the driver. These driver-side cushions are typically of a relatively simple configuration in that they function over a fairly small well-defined area between the driver and the steering column. One such configuration is disclosed in U.S. Pat. No. 5,533,755 to Nelsen et al., issued Jul. 9, 1996, the teachings of which are incorporated herein by reference.
Inflatable cushions for use in the protection of passengers against frontal or side impacts must generally have a more complex configuration since the position of a vehicle passenger may not be well defined and greater distance may exist between the passenger and the surface of the vehicle against which that passenger might be thrown in the event of a collision. Prior cushions for use in such environments are disclosed in U.S. Pat. No. 5,520,416 to Bishop, issued May 28, 1996; U.S. Pat. No. 5,454,594 to Krickl issued Oct. 3, 1995; U.S. Pat. No. 5,423,273 to Hawthorn et al. issued Jun. 13, 1995; U.S. Pat. No. 5,316,337 to Yamaji et al. issued May 31, 1994; U.S. Pat. No. 5,310,216 to Wehner et al. issued May 10, 1994; U.S. Pat. No. 5,090,729 to Watanabe issued Feb. 25, 1992; U.S. Pat. No. 5,087,071 to Wallner et al. issued Feb. 11, 1992; U.S. Pat. No. 4,944,529 to Backhaus issued Jul. 31, 1990; and U.S. Pat. No. 3,792,873 to Buchner et al. issued Feb. 19, 1974, all of which are incorporated herein by reference.
The majority of commercially used restraint cushions are formed of woven fabric materials utilizing multifilament synthetic yarns of materials such as polycster, nylon 6 or nylon 6,6 polymers. Representative fabrics for such use are disclosed in U.S. Pat. No. 4,921,735 to Bloch issued May 1, 1990; U.S. Pat. No. 5,093,163 to Krummheuer et al. issued Mar. 3, 1992; U.S. Pat. No. 5,110,666 to Menzel et al. issued May 5, 1992; U.S. Pat. No. 5,236,775 to Swoboda et al. Aug. 17, 1993; U.S. Pat. No. 5,277,230 to Sollars, Jr. issued Jan. 11, 1994; U.S. Pat. No. 5,356,680 to Krummheuer et al. Oct. 18, 1994; U.S. Pat. No. 5,477,890 to Krummheuer et al. issued Dec. 26, 1995; U.S. Pat. No. 5,508,073 to Kiummheuer et al., issued Apr. 16, 1996; U.S. Pat. No. 5,503,197 to Bower et al. issued Apr. 2, 1996 and U.S. Pat. No. 5,704,402 to Bowen et al. issued Jan. 6, 1998, all of which are incorporated herein by reference.
As will be appreciated, the permeability of the cushion structure is an important factor in determining the rate of inflation and subsequent rapid deflation following the impact event. In order to control the overall permeability of the cushion, it may be desirable to use differing materials in different regions of the cushion. Thus, the use of several fabric panels in construction of the cushion may prove to be a useful design feature. The use of multiple fabric panels in the cushion structure also permits the development of relatively complex three dimensional geometries which may be of benefit in the formation of cushions for passenger side applications wherein a full bodied cushion is desired. While the use of multiple fabric panels provides several advantages in terms of permeability manipulation and geometric design, the use of multiple fabric panels for use in passenger side restraint cushions has historically required the assembly of panels having multiple different geometries involving multiple curved seams.
As will be appreciated, an important consideration in cutting panel structures from a base material is the ability to maximize the number of panels which can be cut from a fixed area through close-packed nesting of the panels. It has been found that minimizing the number of different geometries making up panels in the cushion and using geometries with substantially straight line perimeter configurations generally permits an enhanced number of panels to be cut from the base material. The use of panels having generally straight line profiles has the added benefit of permitting the panels to be attached to one another using substantially straight seams or be substantially formed during the weaving process using a jacquard or dobby loom. Such a straight seam configuration provides a more cost-effective method of producing such airbags.
Furthermore, current vehicle restraint systems comprise an airbag which is attached, through a fastening or adhesive means, to an inflator can. In fact, the standard vehicle restraint system itself generally comprises an inflator can retainer, an inflator can, a housing (in the inflator can is disposed), a folded airbag attached, as noted above, to the housing, an airbag retainer to prevent release of the airbag, and an airbag door. The components parts, the manpower needed to assemble the system, and the extra parts required to properly store the airbag all add up to substantial cost for the consumer. Additionally, since airbags must be three dimensional in shape in order to accord proper cushioning within such a restraint system, the manufacture and, most importantly, folding of such airbags for introduction into and storage within such a system is both cumbersome and costly as well. Without any prior art improvements which adequately address these problems, there is a clear need for producing a cost-effective and manufacturer-friendly vehicle restraint system.
The present invention provides a vehicle restraint system which comprises an airbag and an inflator can assembly, whereby the inflator can of such an assembly is disposed within the airbag itself rather than attached by adhesives, staples, and the like. The particularly preferred airbag configuration may be constructed from two mirror-image body panel sections and one rectilinear center panel section. Upon folding and contacting of the corresponding areas of each of the body panel sections, the sections are connected to one another and to the center panel section by a series of flat, straight seams. Thus, the airbag configuration formed according to the present invention results in highly efficient utilization of materials and may be constructed substantially without the need for complex curved seaming operations. As such, the present invention constitutes a useful advancement over the present art. Furthermore, the rectilinear panel thus forms a looped pocket into which the inflator can, comprising the inflator itself, is disposed. Such a looped pocket is integrated within the structure of the inventive airbag in such a manner that the width of the bag remains at least the same as (and thus never decreases to a distance less than) the width of the looped pocket, itself. With such a feature, the above mentioned substantially straight seaming procedures may be employed over the entire bag and permits full inflation, without impedance, of the bag during an inflation event. The term "substantially straight" in such a term is intended to encompass seams which remain in generally the same line from one distinct point to another without appreciable deviation from that line. Thus, this term is intended to permit human error variations during the sewing process; curved seaming which deviates greater than about 10 degrees, at the most, from the desired seam line is not included in such a term. Although straight seams are preferred, the main inventive features of the airbag remain the width of the airbag in relation to the looped pocket width. The term "looped pocket" is intended to encompass a portion within the inventive airbag into which an airbag inflation canister assembly may be disposed, wherein the assembly is held in place not by the airbag fabric in addition to restraining bolts, but by restraining bolts alone. Thus, the airbag fabric cannot wrap around or over the inflation assembly in such an instance in order to hold the inflation assembly in place during an inflation event.
In a particularly preferred embodiment, the housing of the system surround the looped pocket of the airbag while the inflator can and inflator fit inside both the airbag and the housing simultaneously. Additionally, the utilization of tie-rods within the design of the inventive airbag provides a cost-effective alternative to the standard and currently used three dimensional configurations.